mergefix

#!/usr/bin/env bash
set -e

# Merges feature branch to master branch
# and does all supporting crap like rebasing before merge and
# deleting old branches

GREEN='\033[0;32m'
NC='\033[0m' # No Color

MASTER_BRANCH="master"

ERROR_ON_MASTER_BRANCH=100

MERGE_FLAGS="--ff-only"

MERGE_BRANCH=$MASTER_BRANCH

INITIAL_COMMIT="uninitialised"

for arg
do
  if [ "$arg" = "--no-ff" ]
  then
    MERGE_FLAGS="--no-ff"
  fi
done

while getopts b: option
do
  case "${option}"
    in
    b) MERGE_BRANCH=${OPTARG};;
  esac
done

function get_current_branch {
  git_branch_output=$(git symbolic-ref HEAD)
  current_branch=${git_branch_output#refs/heads/}
}

function get_current_commit {
  current_commit=$(git rev-parse HEAD)
}

function exit_if_on_master_branch {
  get_current_branch
  if [ "$current_branch" = "$MASTER_BRANCH" ]
  then
      echo "Current branch is $MASTER_BRANCH"
      echo "Should be feature branch, exiting"
      exit ${ERROR_ON_MASTER_BRANCH}
  fi
}

function exit_if_on_merge_branch {
  get_current_branch
  if [ "$current_branch" = "$MERGE_BRANCH" ]
  then
      echo "Current branch is $MASTER_BRANCH, the same as target branch"
      echo "Should be feature branch, exiting"
      exit ${ERROR_ON_MASTER_BRANCH}
  fi
}

get_current_branch
get_current_commit

exit_if_on_master_branch
exit_if_on_merge_branch

echo -e "${GREEN}On branch: \"$current_branch\", commit: \"$current_commit\"${NC}"

INITIAL_BRANCH="$current_branch"
INITIAL_COMMIT="$current_commit"

git fetch

echo -e "${GREEN}Rebasing. In case rebase went wrong it can be reverted with: \"git rebase --abort\"${NC}"
echo -e "${GREEN}In case something else went wrong, current branch can be restored using${NC}"
echo -e "${GREEN}git checkout $INITIAL_BRANCH;git reset --hard $current_commit${NC}"

git rebase origin/$MERGE_BRANCH

# Extra safe check so we don't push force master or target
exit_if_on_master_branch
exit_if_on_merge_branch
git push --force

git checkout $MERGE_BRANCH

git pull --ff-only

git merge $INITIAL_BRANCH $MERGE_FLAGS

git push

echo -e "${GREEN}Deleting source branch. In case something went wrong it can be restored using${NC}"
echo -e "${GREEN}git checkout -b $INITIAL_BRANCH $INITIAL_COMMIT${NC}"

git branch --delete $INITIAL_BRANCH

# Extra safe check so we don't delete master :)
if [ "$INITIAL_BRANCH" = "$MASTER_BRANCH" ]
then
    echo "Current branch is $MASTER_BRANCH"
    echo "Should be feature branch, exiting"
    exit 1
fi

# Extra safe check so we don't delete target branch :)
if [ "$INITIAL_BRANCH" = "$MERGE_BRANCH" ]
then
    echo "Current branch is $MERGE_BRANCH"
    echo "Should be feature branch, exiting"
    exit 1
fi

git push origin --delete $INITIAL_BRANCH

echo "Merge success, on $MERGE_BRANCH branch now"